λευκόπρωκτος
From LSJ
οἷς πρόθεσίς ἐστιν ἀδικεῖν, παρ' αὐτοῖς οὐδὲ δικαία ἀπολογία ἰσχύει → not even a just excuse means anything to those bent on injustice | the tyrant will always find a pretext for his tyranny | any excuse will serve a tyrant
English (LSJ)
ον,
A with white πρωκτός, a play on the words εὐρύπρωκτος and λευκός 11.1c, conveying a notion of cowardice, Call.Com.11 (s.v.l.).
German (Pape)
[Seite 34] mit weißem Hintern, Callias bei Schol. Ar. Av. 151, = λευκόπυγος, weibisch, feig.